F450 Dana 80 Clutch rebuild

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Hondajimz

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My buddy has a 2018 F450 dually and has smoked the clutches in the rear diff. He has been running 37's and deleted/tuned the truck. Looking for advise on upgrading to heavy duty clutches. Can anybody recommend what kit he should order ?

 
The factory is a good diff,  what diff cover,  if the cover was changed out to a high capacity it might have smoked it,  the large diff covers do not lubricate well on the fords,  

 
Mine has 37.5'' tires and 140K on the rear diff and still super tight, 

 
J Alper said:
The factory is a good diff,  what diff cover,  if the cover was changed out to a high capacity it might have smoked it,  the large diff covers do not lubricate well on the fords,  
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I'm not sure if it's stock. I will have to ask. He's used the truck a lot pulling people out of the dunes when they're stuck. Last week in Oregon he got stuck pulling his 5vr into camp. He kept trying to go forward / reverse to get out and sometimes it sounded like he wasn't in gear when he hammered the gas. Pretty sure that was his clutches.

At another point he tried pulling someone out that was stuck and he buried himself. Only the right front and left rear wheel were turning. The right front dug a hole and the left rear was up in the air. The front was buried to the frame. 

f450.jpg

 
Hondajimz said:
...sometimes it sounded like he wasn't in gear when he hammered the gas...
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That sounds like trans/torque converter if none of the tires were spinning when he did that.  Even a completely shot LSD will just act like an open diff and one tire *has* to spin if the pinion is being spun.  Tell him it's time to detail it up and trade it in on a '21 with the 10-speed. 😉

As for the front, it's an open diff so whichever tire has the least traction will spin.  Outside of the Tremor package I don't think Ford put LSDs in the front of Super Duties, but I could be wrong (and the Tremor came out after '18 and isn't available on 450s).  In the rear even a good limited slip is only going to do so much when a tire is fully in the air like that - and continuing to spin it is just going to eat the clutches up more. 

One "trick" is to hold some brake pressure on while hitting the throttle to provide some resistance on the free-spinning wheel.  It's much more effective with torque-sensing diffs like a Torsen (in fact, H1 hummer military manuals actually recommend this tactic for the front and rear Torsens) but it can help a bit with a clutch-type LSD.  

Also, one other thing, isn't the rear axle in that thing a M300, not a Dana 80? 

-TJ

 
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Here's one option: https://eastcoastgearsupply.com/i-23993849-dana-m300-41-spline-trak-lok-f450-550.html (but I think stock is 37 spline axle shafts, so he'd have to get accompanying upgraded axle shafts).  It really seems like there's not much else out there for the M300.  

Dana-M300-11.8-Rear-Axle-Parts-Catalog-1.jpg


It looks like the OEM Trac-Lok for the 37 spline unit that *should* be in his F450 would be DAN10043381 or DAN10043382 depending on his stock gear ratio.  I'd assume 4.10 or numerically higher, in which case it'd be the 82.

-TJ

 
Instead of the clutches see if they make a E- Locker, way better than any traction locker.

 
J Alper said:
Mine has 37.5'' tires and 140K on the rear diff and still super tight, 
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I'm on 37's too and have 320k on my truck with no issues in the trans or axles. Probably 100k of those miles was towing a 3705 with 2 slides to the river and G

 
Agricon said:
Instead of the clutches see if they make a E- Locker, way better than any traction locker.
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He has onboard air so I think he's going to go with an air locker. Thanks for the suggestion though.

 
Hondajimz said:
He has onboard air so I think he's going to go with an air locker. Thanks for the suggestion though.
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I’ve spent a lot of time on the side of the trail helping buddies repair air lines. Leaks everywhere: lines, fittings, solenoids, engagement collar (worst). All kill the locker, or at least make you listen to the compressor all the time. 

 
tjZ06 said:
I don't think ARB makes a locker for the M300...

-TJ
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I guess he needs to figure out what he has and then decide from there to go air locker or E lock. I'm sure he'll be giving you a call to ask for advise. Thank you for the info and link you posted.

 
Hondajimz said:
I guess he needs to figure out what he has and then decide from there to go air locker or E lock. I'm sure he'll be giving you a call to ask for advise. Thank you for the info and link you posted.
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I'm pretty sure it'll be the M300 (which is a beef-cake axle... bigger/stronger than a D80) which doesn't have Air or E-locker options. 😞 I haven't found anything out there other than the factory Trac-Loc.  I'm still sort of concerned about his trans/converter if he was in-gear revving up with no wheel movement intermittently. 

-TJ 

 
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